Marcos German-Dominguez waves a rainbow flag in front of the U.S. Supreme Court on March 26. / Andrew P. Scott, USA TODAY

by Richard Wolf and Kevin Johnson, USA TODAY

by Richard Wolf and Kevin Johnson, USA TODAY

WASHINGTON -- The Supreme Court began two days of historic oral arguments Tuesday on a civil rights issue with sweeping moral, religious and social overtones: Can members of the same sex get married? At times, it seemed the court regretted taking the case.

As thousands of supporters and opponents of gay marriage marched and demonstrated outside, a select few hundred ‚?? some of whom waited up to five days for a seat ‚?? sat hushed as the nine justices peppered questions at attorneys for both sides.

The discussion often focused on technical issues that could thwart both sides' desire for a clear result. Several justices, led by Anthony Kennedy, the likely swing vote, questioned whether the case even belonged before them.

The case focuses on California's four-year-old same-sex marriage ban, known as Proposition 8. It will be followed Wednesday by a challenge to the federal Defense of Marriage Act, which denies financial and other benefits to legally married same-sex couples.

After nearly 90 minutes of debate -- a full half-hour more than scheduled -- several things appeared clear:

‚?Ę Chief Justice John Roberts was skeptical of gays' and lesbians' right to marry. "This institution's been around since time immemorial," he said.

‚?Ę Kennedy, as usual, appeared torn and looking for an escape route. "I just wonder if the case was properly granted," he said.

‚?Ę The four liberal justices appeared aligned with those favoring same-sex marriage. Justice Elena Kagan led a round of questions about the importance of procreation, a key argument of gay marriage opponents. What about infertile couples, those over 55, and prisoners? They can't procreate, either.

‚?Ę Justice Antonin Scalia and the other conservatives appeared more likely to side with Proposition 8's supporters -- and particularly with the argument that the court should use caution before green-lighting gay marriages.

"It may turn out to be a good thing, it may turn out to be a bad thing," said Justice Samuel Alito, but same-sex marriage "is newer than cellphones and the Internet."

Theodore Olson, lead attorney for the gay and lesbian couples challenging Proposition 8, appeared ebullient on the court steps after the argument was concluded. But he acknowledged the difficulty in reading judicial tea leaves.

"We are confident with where the American people are going with this,'' Olson said in reference to growing public support for gay marriage. "We don't know where the Supreme Court is going.''

The justices wasted no time Tuesday in tackling the issue, peppering Charles Cooper, the lead attorney for proponents of the proposition, with a series of questions, including whether California voters even had authority to appeal a lower court ruling that blocked enforcement of the marriage ban.

Roberts, Kagan and Justices Ruth Bader Ginsburg and Sonia Sotomayor repeatedly questioned Cooper, with Ginsburg once suggesting that voters had "no proprietary interest" in the matter after they had cast their ballots in November 2008.

In a discussion over the possible "harm" that could result in allowing same-sex marriage, Kennedy noted that there were nearly 40,000 children in California with same-sex parents who would likely want their parents to have the same rights as heterosexual parents.

"The voice of the children is important, don't you think?'' Kennedy asked.

Scalia countered, saying that not enough information is known to determine whether same-sex parenting can be harmful to children.

"There is no satisfactory answer at this point in time," Scalia said.

Cooper argued that it was time to "hit the pause button" in California.

"Redefining marriage as a genderless institution," Cooper said, would likely "harm the institution of marriage."

Whatever decision the court ultimately reaches by late June will mark a milestone on an issue that has divided the nation for decades. Thirty-eight states have instituted bans on gay marriage; nine states and the District of Columbia allow it.

If the court rules broadly against California's ban, it would implicate other state prohibitions, most likely leading to lawsuits and repeal efforts from coast to coast. If the ban is upheld, it could stall the gay-rights movement for years to come. Either way, the losing side is sure to mount new legal, legislative and lobbying campaigns.

The court could rule more narrowly, limiting its ruling to eight states that allow the benefits of marriage without the title; to California only, because it took away a right that previously existed; or by deciding that the case is not properly before the justices because the four gay and lesbian plaintiffs and the state of California are on the same side. California has refused to defend its ban in court.

That same dilemma could influence Wednesday's debate as well. The federal government has refused to defend the Defense of Marriage Act, leaving it to House Republicans to argue the case in court. But it hasn't returned the $363,000 in estate taxes paid by lesbian widow Edith Windsor after her same-sex spouse's death, either.

Whatever the court rules, public opinion appears to be trending in favor of gay marriage. A December poll in USA TODAY showed 53% support for gay marriage, up from 40% in 2009. A more recent Washington Post/ABC poll showed 58% approval. And a Pew Research Center survey this month showed that support has soared to 70% among young people ages 18-32. Nearly one-third of all supporters say they have changed their minds, most often because they know someone who is gay.

The California Supreme Court cleared the way for gay marriages four years ago, and quickly about 18,000 couples tied the knot. That led opponents of same-sex marriage to demand a voter referendum outlawing gay marriage, which passed narrowly in November 2008.

The original lawsuit against Proposition 8, filed by a gay couple and a lesbian couple, has won at both federal courts leading to the Supreme Court. The district court said the law violated the Constitution's equal protection clause because it was "premised on the belief that same-sex couples simply are not as good as opposite-sex couples." The appeals court ruled more narrowly that voters could not take away a right previously granted to the state's gays and lesbians.

Last year, following a string of gay marriage bans in other states -- including North Carolina, which hosted the Democratic National Convention, but where voters banned gay marriage with 61% of the vote -- the gay-rights movement rebounded. President Obama declared his support for same-sex marriage during his re-election campaign. Voters in Maine, Maryland and Washington legalized gay marriage, and Minnesota voters rejected a statewide ban.

Rather than remaining on the sidelines in the California debate, the Obama administration came out forcefully last month against the ban and decided to help argue the case in court. It singled out California and seven other states that allow civil unions or domestic partnerships, arguing they cannot deny the title of marriage.

"Proposition 8's denial of marriage to same-sex couples, particularly where California at the same time grants same-sex partners all the substantive rights of marriage, violates equal protection," the administration's brief states.

Making the case for gay marriage was Theodore Olson, the conservative former U.S. solicitor general who teamed up with liberal David Boies on the case. They were representing two couples: Kris Perry and Sandy Stier, lesbian parents of four sons, and Jeff Zarrillo and Paul Katami, a gay couple who want to marry and raise a family.

"In this country, as children, we learned that there is a fundamental principle that all people are created equal,'' Perry said after the oral arguments. "We look forward to the day when Proposition 8 is finally and officially eliminated.''

Arguing in support of Proposition 8 was Cooper, the attorney representing the original proponents of the referendum. They argue that marriage is based upon producing and raising children by a mother and father. They say forcing opponents to recognize same-sex marriages would infringe on their religious beliefs. And they say states and voters should be left alone to make their own decisions.

Andrew Pugno, general counsel for the Protect Marriage Coalition and supporter of the ban, said Cooper presented a "winning case.''

"I thought that the hearing went very well,'' he said.

About 100 "friend of the court" briefs were filed, equally divided between the two sides. While support for Proposition 8 came largely from religious and conservative political groups, opposition ran the gamut from Fortune 500 companies who called marriage equality "a business imperative" to more than 100 prominent Republicans and two National Football League stars.